<!DOCTYPE html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
		<style type="text/css">
			#div1 div,
			#div2 div {
				width: 200px;
				height: 200px;
				border: 1px #000 solid;
				display: none;
			}
			.active {
				background: red;
			}
		</style>
	</head>

	<body>
		<div id="div1">
			<input class="active" type="button" value="1">
			<input type="button" value="2">
			<input type="button" value="3">
			<div style="display:block">11111</div>
			<div>22222</div>
			<div>33333</div>
		</div>
		<script src="index.js" type="text/javascript" charset="utf-8"></script>
	</body>

</html>